What are the common types of whisky casks?

Sherry Cask (480~600 Liters)

Made of European oak or American white oak, sherry casks are widely used for aging Spanish sherry and serve as mainstream casks to shape classic whisky flavors.

Whisky matured in sherry casks features a full-bodied texture and rich fruity notes. It delivers flavors of dried fruits, honey, dark chocolate, nuts, pepper, caramel and orange, with the liquid showing a deep amber color.

Main Flavors

Sherry casks naturally carry rich aromas of fortified wine and distinct raisin notes. Whisky aged here is smooth with abundant floral and fruity scents. It has prominent raisin taste mixed with hints of chocolate, spices and various preserved fruits, presenting rich and layered flavors.

Representative Products: The Macallan 12 Years Old Sherry Single Cask, Arran Sherry Cask Strength, Glenfiddich 12 Years Old Angel's Share Sherry and so on.

Bourbon Barrel (180~200 Liters)

Also known as American Standard Barrel (ASB), it is a toasted oak barrel previously used to age American bourbon whisky. With low cost and sufficient supply, it is commonly used for maturing whiskies ranging from daily drinking spirits to rare premium releases.

Bourbon barrels are the most widely used oak casks in the Scotch whisky industry, with around 90% of all whiskies aged in such barrels. They gain great popularity due to large stock and low price, while a sherry cask costs roughly ten times more than a bourbon barrel.

Laws stipulate that bourbon whisky must be matured in brand-new American oak casks. The used barrels are exported to Scotland as economical alternatives to sherry casks. In the early days, most Scotch whiskies were aged in shipped sherry casks.

A standard bourbon barrel holds 53 gallons, approximately 180 to 200 liters, crafted from 30-year-old American white oak. It undergoes open flame toasting during production, divided into four grades from light to heavy with heating time of 15 seconds, 30 seconds, 45 seconds and 1 minute respectively. The fourth-grade heavy charring carbonizes the wood surface and forms uneven shiny black textures similar to alligator skin, which is called alligator char. Distilleries can customize toasting duration according to flavor demands.

Main Flavors

Whisky aged in bourbon barrels is pale golden in color with soft and delicate texture. It is dominated by elegant floral, fruity and woody aromas including vanilla, coconut, honey, almond, cream, caramel and leather.

Representative Products: Arran Bourbon Cask, Kavalan Classic Soloist Bourbon Cask, Bruichladdich Classic Barley and so on.

Hogshead (230~250 Liters)

Classified by capacity instead of flavor type, hogshead is also nicknamed hoggie. Originally applied to age sherry and bourbon whisky, it is now mostly used for secondary maturation, ranking as the third most common oak cask after sherry casks and bourbon barrels.

It is also called reconditioned cask, mostly reassembled from used bourbon barrels with a capacity of 225 to 250 liters. Some hogsheads are pieced together from rare sherry cask timbers, known as Sherry Hogsheads. Extremely scarce, they are generally priced at 400 to 500 British pounds, which partly explains the higher price of sherry-cask-aged whisky.

Main Flavors

Most hogsheads are reconstructed from bourbon or sherry casks, so whisky aged in them combines the flavor characteristics of both, owning more complex tastes and great aging potential.

Larger casks mean smaller contact area between spirit and wood, leading to milder aging speed. Oak flavor substances can blend into the liquor steadily, making hogsheads ideal for long-term maturation.

Representative Products: Mortlach 1995 Bourbon Hogshead, Yamazaki 13 Years Old Hogshead, The Macallan 2018 Sherry Hogshead, Arran Sherry Hogshead and so on.